1. Field of the Invention
The invention relates to a system using data from an address location in one memory to address data in a second memory for reordering data.
2. Description of the Prior Art
Development of the data processing field has resulted in the use of a plurality of different codes, or character identifications. For example, one code may be comprised of 8 bits, whereas another code may be comprised of 6 bits. In still another example, two 8-bit codes may be used comprising different symbols. Before systems organized for different codes can be interconnected, the two codes, or the systems, must be made compatible. Since it may be too expensive to redesign hardware or to change codes for such applications, it would be better to provide a means for converting from one code to another. The conversion means may by a separate system although in a practical system, a special command may be provided in a data processing system for using conversion hardware in the system.
Ordinarily, the conversion means may be a computer program which executes a sub-routine each time the presence of a different code is detected. In other systems, the different codes may be stored together so that each time one code is detected, the equivalent code stored at an adjacent location is read out. Twice the storage capacity is required in dual storage systems.
Such systems require time and use storage space that could be used for other purposes. It would be more desirable to provide a simple code converter system which could convert directly from one code to another. In that manner, systems using one code could be connected through the converter to the systems using a different code. There would be no requirement to re-design or program sub-routines.
There would, however, be a requirement for storing the conversion data prior to an interconnection. Different data could be stored to accommodate various conversions.
There is also a requirement for a system which can easily reorder data. Since a code conversion system in effect reorders data, the same system can be used for both applications by selectively addressing the data in the memories.